2008/7/14 Florian G. Pflug <[EMAIL PROTECTED]>: > Pavel Stehule wrote: >>> >>> One issue that just occurred to me: what if a variadic function wants to >>> turn around and call another variadic function, passing the same array >>> argument on to the second one? This is closely akin >>> to the problem faced by C "..." functions, and the solutions are pretty >>> ugly (sprintf vs vsprintf for instance). Can we do any better? At least in >>> the polymorphic case, I'm not sure we can :-(. >>> maybe with some flag like PARAMS? >> >> SELECT least(PARAMS ARRAY[1,2,3,4,5,6]) > > Just FYI, this is more or less how ruby handles variadic functions - a > "*" before the last argument in the function's *definition* causes all > additional arguments to be stored in an array, while a "*" before the > last argument in a function *call* expands an array into single arguments. > > So, you could e.g do > def variadic1(a, b, *c) > # c is in array containing all parameters after second one. > end > > def variadic_wrapper(a, *b) > variadic1("foobar", a, *b) > end > > So there is precedent for the "flag idea" too. Plus, I kind of like the > idea of using the same syntax for both wrapping and unwrapping of variadic > arguments. > > regards, Florian Pflug >
ok - it's possible, I''l look in this direction - and it's should be usable in plpgsql - we should be able call variadic functions from plpgsql with immutable number of arguments without dynamic SQL. sample: select mleast(variadic array[1,2,3,4,5]); so I wouldn't do ruby from plpgsql :). Still my goal is well support for libraries like JSON or XML. select json_object(name as 'name', prop as 'prop') --> '[name: xxxx, prop: yyyy ... It's not strong like SQL/XML, but it is independent on parser, and could exists outside. So my next step is named parameters in SELECT statement. Regards Pavel Stehule > -- Sent via pgsql-patches mailing list (pgsql-patches@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-patches